<?php
$msg = '
    asdas asdasd asdas aline_ca1@hotmail.com asdasd asdas asdas
    asdas asdasd asdas aline_ca2@hotmail.com asdasd asdas asdas
';
preg_match('/([_\-.a-zA-Z\d]{1,30})@([_\-.a-zA-Z\d]{1,30})([.]{1})([_\-.a-zA-Z]{1,10})/', $msg, $output);

var_dump($output);